Micro Quadcopter QUADX Arduino Pro Mini 3.3V Problems

[td75]

Hi everyone! Hope someone can help with problems I've been having with my micro quadcopter. I've built a micro quadcopter running on 1s lipo (32g without battery) that's been giving very unusual problems and cannot set this up correctly. I had it working with 5v pro mini but after a short period of flying it would just go crazy, flip over and crash. I found that the WMP would just stop responding. I figured this was because I was powering up the 5v pro mini with only 3.7V lipo and this was causing dropouts. Anyway have now fitted a 3.3v pro mini but having very unusual problems. First of all I cannot get this working by powering WMP from pin 12. LED just stays solid. Once I connect to VCC this now works and I can arm motors. The second problem is the minimum running value for ESC. On the 5v pro mini I had minimum value set to 1100 and it worked well. On the 3.3v pro mini I have to set this down to 500. Now the ESC will initialize (WMP connected to VCC) and I can arm the motors. Problem is this minimum speed does not run the motors in idle as expected. I can now throttle up and WMP seems to be working correctly. Throttle values seem incorrect in multiwiiconfig and are erratic. Now the very strange thing is when I disarm, the motors throttle up on there own but cannot be controlled by throttle, until I rearm then they stop and I can use throttle again. I have tried changing many different settings in sketch and on transmitter but cannot figure this out. Is there a problem using this software with the 3.3v pro mini with my setup or are there some setting that need to be changed? I have tried using MultiWii versions 1.7, 1.8 & 1.9. Would I be better off going back to 5V pro mini and using a 3v to 5v DC to DC converter? Don't really want to add much more weight though. Also the 3A ESC can only run off 1s lipo so 2s is not an option with this setup.

Current setup:

- Sparkfun Ardunino pro mini 3.3v
- WMP original
- 4x ADH30S Micro brushless outrunner 6100kv
- 4 3x2 Propellers
- 4x HobbyKing XP 3A 1S 0.7g Brushless Speed Controller
- 1s 3.7v 700mah lipo
- Rx31 DSM2 Ultra Micro Receiver
- Spektrum DX8

Really appreciate any advice on this!

[mr.rc-cam]

Some initial comments:

The 5V Pro Mini is 16MHz. That said, I suspect that your Pro Mini 3.3V CPU is the 8MHz version. If you use the 8MHz 3.3V CPU some of the time sensitive code in the software may cause grief. For example, this is probably the reason you had to drop the min throttle value to 500. Some of the timing issues will be avoided if you have chosen the correct CPU in the Arduino IDE's Tools->Board menu. But even so, be prepared to modify the code if you have a 8MHz CPU.

Also, with only a 1S for power, the peak currents from motor commutation will cause VCC voltage spikes that may dip below the recommended supply voltage. If you experience this problem then a LC type supply filter may offer some relief. But using a 5V CPU and one of those cheap HobbyCity 1S-to-5V VReg boosters may weigh less than the necessary LC power filter components and eliminate some other hardships too.

[td75]

Thanks for your reply. Yes the 3.3V is the 8MHz version. I didn't realize the current code wasn't suited to 8MHz. Not too clued up with the coding so guess this would not be a good option. This guy here has a similar setup with 1s and it seems to fly very well: http://youtu.be/AZ7Xt2b61Us - not sure what CPU he is using as looks like he has made his own PCB. I guess it will be best to go back to 16MHz and try a booster on this..

[mr.rc-cam]

When you loaded MWC V1.9 did you have the correct CPU chosen in the IDE's Tools->Board? That is to say, was the 3.3V 8MHz CPU selected? If you had the 16MHz CPU chosen then that would certainly reduce your chances for success.

[td75]

Yes I've actually tried both board options, 16MHz & 8MHz ATmega 328, but both give same results..

[mr.rc-cam]

If you are using the 8MHz Tools->Board selection then that takes care of a few things related to CPU timing. Software wise, getting the 8MHz CPU to work might be practical. So it may be best to wait for more advice on the project before giving up.

[td75]

Has anyone successfully used a 3.3V Pro Mini 8MHz with WMP running on 1S or has anyone successfully run a 5V Pro Mini 16MHz with 1S?

Do you think this would work for 1S setup on 5V board? http://www.sparkfun.com/products/8290

[Dwest2828]

I was thinking of having a simular configuration and was wondering this same thing. I already have a 5v 16MHZ Arduino but wanted to run a 1S battery with the <1g ESC's. My thinking was to either step up the voltage on the power input to the Arduino to 5v or either step down the voltage to the ESC's (this would require me to have a 2S battery pack). I really would just rather get the 3.3v/8MHZ Arduino and be done with it. Are there any other configuration changes to be aware of that I could be overlooking. td75, did you get your set up figured out?

[Kayle]

Hi,

I fly my "femto quad" with an arduino pro mini 16mhz at 3,3v. The 3,3v is generated by a mcp1252 buck/boost converter. I don't have any problem to fly with 16mhz and 3,3v.

Greetings kayle

[Mgl]

Can u tell us how you made it? Do you mean your quad uses 5.5v 16mHz ardiuno and runs on 1s? We want to build one. Can you make video? Thanks

[Kayle]

Hi,

yes i use an 5V 16Mhz arduino and it runs on 3,3V ( generated by a mcp1252 ). Just plug 3,3V to the VCC Pin. Don´t use RAW Pin. I don´t have a video yet. But i can make on next year.

[Mgl]

Can you post your set up? Motors, esc, receiver that you used. What it total weight and flying time? Thanks

Mgl

[Kayle]

Hi,

Motors: Xtwin with props
ESC: IRLML2502 MOSFET
Receiver: Deltang DSM2 0,23g

Total weight: 17,8g ( incl. LED PWM with extra Attiny44 Controller )

Flight time ? Don´t know. I do only some flight test until yet.

Kayle

[Mgl]

That is awesome. I want to make one. But i am not engineer, i need your help. Would you mind if i asked you make short tutorial how all component connected each other. I have built multiwiicopter with 2s battery. I want to make one for 1s. If you make short tutorial, many of us would be thankful for you.
Please

Thanks

Mgl

[Kayle]

Next Year i will make a tutorial on my Homepage. I post the link if the tutorial is online.

Kayle

[Mgl]

Thank you. I will wait. Do not forget to make video as well. I will start collecting components. I want to make brushless and brushed.

Happy Holidays

[KeesvR]

Maybe you can use this one: http://www.flytron.com/multicopter-part ... lity-.html

[Kayle]

hi,

that´s the same such the 5V 16Mhz -> only with 3,3V regulator. You can use a 5V Arduino and put the 3,3V at the VCC pin.

kayle

[KeesvR]

I thought this one was different because you don't need a LLC.

As i understand it's better to use a LLC to get 5 volt on the data lines.

[Kayle]

Hi,

I thought this one was different because you don't need a LLC.

That´s correct.

As i understand it's better to use a LLC to get 5 volt on the data lines.

When you use a Gyro or ACC whose Datalines are 5V tolerant thats ok. But when you use for example ITG3200 and ADXL345 or BMA180 you could damage the sensor with 5V on Dataline.

Because i use only a 1S Lipo i don´t need a LLC an my Datalines are all 3,3V. Thats perfect for the sensors.

Kayle

[Mgl]

Hi Kayle

What is weight of twin x motor with prop? Motor is smaller than blade msr tail motor? What is weight of your quad frame? What did you use for? I am thinking to use carbon tube 2mm. Did you use wii MPlus or something else?

Can you tell me how to make esc using Mosfet and how to connect power converter to arduino mini pro? Output voltage will be set at 3.3v by connecting select pin (8 pin) to V in. Connect 1mF capacitor between pin 5 and pin 6. Am i right?

Thanks

Mgl

[Kayle]

Hello all,

My little quad fly great. Look at Picture/Video section - femto x quad.

Kayle